<template>
	<div class="drawer">
		<div :class="maskClass" @click="closeByMask"></div>
		<div :class="mainClass" :style="mainStyle" class="main">
			<div class="drawer-head">
				<span>{{ title }}</span>
				<span class="close-btn" v-show="closable" @click="closeByButton">X</span>
			</div>
			<div class="drawer-body"><slot /></div>
		</div>
	</div>
</template>

<script>
export default {
	props: {
		// 是否打开
		display: {
			type: Boolean
		},

		// 标题
		title: {
			type: String,
			default: '标题'
		},

		// 是否显示关闭按钮
		closable: {
			type: Boolean,
			default: true
		},

		// 是否显示遮罩
		mask: {
			type: Boolean,
			default: true
		},

		// 是否点击遮罩关闭
		maskClosable: {
			type: Boolean,
			default: true
		},

		// 宽度
		width: {
			type: String,
			default: '400px'
		},

		// 是否在父级元素中打开
		inside: {
			type: Boolean,
			default: false
		}
	},
	computed: {
		maskClass: function() {
			return {
				'mask-show': this.mask && this.display,
				'mask-hide': !(this.mask && this.display),
				inside: this.inside
			};
		},
		mainClass: function() {
			return {
				'main-show': this.display,
				'main-hide': !this.display,
				inside: this.inside
			};
		},
		mainStyle: function() {
			return {
				width: this.width,
				right: this.display ? '0' : `-${this.width}`,
				borderLeft: this.mask ? 'none' : '1px solid #eee'
			};
		}
	},
	mounted() {
		if (this.inside) {
			let box = this.$el.parentNode;
			box.style.position = 'relative';
		}
	},
	methods: {
		closeByMask() {
			this.maskClosable && this.$emit('update:display', false);
		},
		closeByButton() {
			this.$emit('update:display', false);
		}
	}
};
</script>

<style lang="less" rel="stylesheet/less">
.drawer {
	height: 100%;
	height: 100%;
	/* 遮罩 */
	.mask-show {
		position: fixed;
		top: 0;
		left: 0;
		width: 100%;
		height: 100%;
		z-index: 10;
		background-color: rgba(0, 0, 0, 0.5);
		opacity: 1;
		transition: opacity 0.5s;
	}
	.mask-hide {
		opacity: 0;
		transition: opacity 0.5s;
	}

	/* 滑块 */
	.main {
		position: fixed;
		z-index: 10;
		top: 0;
		height: 100%;
		background: #fff;
		transition: all 0.5s;
	}
	.main-show {
		opacity: 1;
	}
	.main-hide {
		opacity: 0;
	}

	/* 某个元素内部显示 */
	.inside {
		position: absolute;
	}

	/* 其他样式 */
	.drawer-head {
		display: flex;
		justify-content: space-between;
		height: 45px;
		line-height: 45px;
		padding: 0 15px;
		font-size: 14px;
		font-weight: bold;
		border-bottom: 1px solid #eee;
		.close-btn {
			display: inline-block;
			cursor: pointer;
			height: 100%;
			padding-left: 20px;
		}
	}
	.drawer-body {
		font-size: 14px;
		padding: 15px;
	}
}
</style>
